Different Types of Projective Synchronization in a Class of Time-Delayed Chaotic Systems Using Active Control Approach

We study different types of projective synchronization （projective-anticipating, projective, and projectivelag synchronization） in a class of time-delayed chaotic systems related to optical bistable or hybrid optical bistable devices. We relax some limitations of previous work, where the scaling factor a can not be any desired value. In this paper, we achieve projective-anticipating, projective, and projective-lag synchronization without the limitation of a. A suitable controller is chosen using active control approach. Based on the Lyapunov stability theory, we derive the sufficient stability condition through theoretical analysis. The analytical results are validated by the numerical simulations using Ikeda model and Mackey-Glass model.

Clock synchronization design and evaluation for trigger-less data acquisition system

For modern particle physics experiments,trigger-less data acquisition(DAQ) system has been put into practice because of the need of reaction multiplicity and trigger flexibility.In such new DAQ systems,global synchronized clock plays an important role because it affects the granularity of time slice and precision of reference clock.In this paper,a novel synchronized clock distribution method is proposed.With the help of modulation technique,master clock module distributes system clock to each slave module.To synchronize slave clocks,the propagation delay is adjusted and the clock phase is aligned by an FPGA chip automatically.Furthermore,an ADCbased method is proposed to evaluate the performance of multi-module clock synchronization simultaneously.The experiments of a prototype system show that slave clocks can be synchronized less than 100 ps over 150 m range.The proposed method is simple and flexible,and it can be used in trigger-less DAQ system and other applications of clock distribution preciously.

Synchronization of Markovian jumping complex networks with event-triggered control

This paper investigates event-triggered synchronization for complex networks with Markovian jumping parameters.Nonlinear dynamics with Markovian jumping parameters is considered for each node in a complex network. By utilizing the proposed event-triggered strategy, and based on the Lyapunov functional method and linear matrix inequality technology,some sufficient conditions for synchronization of complex networks are derived whether the transition rate matrix for the Markov process is completely known or not. Finally, a numerical example is presented to illustrate the effectiveness of the proposed theoretical results.

Development of a High Power Programmable Precise Time-Delay Trigger/Ignition System for MFCG

High-power precise delay trigger/ignition system is a programmable pulse generator developed for experiment controlling in explosively driven magnetic flux compression generators. Precise delay pulses are generated by the digital circuit, after being magnified and sharpened through multistage isolated amplifiers and rising edge sharpening device, high-voltage steep delay pulses with precision less than μs level are obtained. This system has been used in our compact magnetic flux compression generator experiments in place of the traditional primaeord delay device.

Global exponential synchronization between Lü system and Chen system with unknown parameters and channel time-delay

This paper proposes a nonlinear feedback control method to realize global exponential synchronization with channel time-delay between the Lfi system and Chen system, which are regarded as the drive system and the response system respectiveiy. Some effective observers are produced to identify the unknown parameters of the Lii system. Based on the Lyapunov stability theory and linear matrix inequality technique, some sufficient conditions of global exponential synchronization of the two chaotic systems are derived. Simulation results show the effectiveness and feasibility of the proposed controller.

Adaptive synchronization of a class of fractional-order complex-valued chaotic neural network with time-delay

This paper is concerned with the adaptive synchronization of fractional-order complex-valued chaotic neural networks(FOCVCNNs)with time-delay.The chaotic behaviors of a class of fractional-order complex-valued neural network are investigated.Meanwhile,based on the complex-valued inequalities of fractional-order derivatives and the stability theory of fractional-order complex-valued systems,a new adaptive controller and new complex-valued update laws are proposed to construct a synchronization control model for fractional-order complex-valued chaotic neural networks.Finally,the numerical simulation results are presented to illustrate the effectiveness of the developed synchronization scheme.

Impulsive synchronization of two coupled complex networks with time-delayed dynamical nodes

In this paper, we investigate the impulsive synchronization between two coupled complex networks with time- delayed dynamical nodes. Based on the Lyapunov stability, the linear feedback control and the impulsive control theories, the linear feedback and the impulsive controllers are designed separately. By using the generalized Barbalat＇s lemma, the global asymptotic impulsive synchronization of the drive-response complex networks is derived and some corresponding sufficient conditions are also obtained. Numerical examples are presented to verify the effectiveness and the correctness of the synchronization criteria.

Generalized Synchronization of Time-Delayed Discrete Systems

This paper establishes two theorems for two time-delayed （chaotic） discrete systems to achieve timedelayed generalized synchronization （TDGS）. These two theorems uncover the genera/forms of two TDGS systems via a prescribed transformation. As examples, we convert the Lorenz three-dimensional chaotic map to an equal time-delayed system as the driving system, and construct the TDGS driven systems according to the Theorems 1 and 2. Numerical simulations demonstrate the effectiveness of the proposed theorems.

Fixed-Time Adaptive Time-Varying Matrix Projective Synchronization of Time-Delayed Chaotic Systems with Different Dimensions

This paper deals with the fixed-time adaptive time-varying matrix projective synchronization(ATVMPS)of different dimensional chaotic systems(DDCSs)with time delays and unknown parameters.Firstly,to estimate the unknown parameters,adaptive parameter updated laws are designed.Secondly,to realize the fixed-time ATVMPS of the time-delayed DDCSs,an adaptive delay-unrelated controller is designed,where time delays of chaotic systems are known or unknown.Thirdly,some simple fixed-time ATVMPS criteria are deduced,and the rigorous proof is provided by employing the inequality technique and Lyapunov theory.Furthermore,the settling time of fixed-time synchronization(Fix-TS)is obtained,which depends only on controller parameters and system parameters and is independent of the system’s initial states.Finally,simulation examples are presented to validate the theoretical analysis.

Time-Delay Effects on Synchronization of Coupled Slow-Fast Systems

Time-delay effects on synchronization features of delay-coupled slow-fast van der Pol systems are investigated in the present paper. The synchronization mechanism of “slow-manifold adjustment” is firstly described on the basis of geometric singular perturbation theory. Then, the impact of time delay on the structure of the slow manifold of synchronized system is obtained by using the method of stability switch, and thus, time-delay effects on synchronization features are stated. It is shown the time delay cannot qualitatively affect the synchronization mechanism, however, it can result in the drift of the optimal coupling strength.

Photoconductive semiconductor switch-based triggering with 1 ns jitter for trigatron

Synchronization for multiple-pulse at nanosecond range shows a great value on the power multiplication and synchronous electric fieldsapplications. Nanosecond or sub-ns jitter synchronization is essential for the improved working efficiency of the large amounts of pulse modulesand accurate requirements for the power coherent combining applications. This paper presents a trigger generator based on a laser diodetriggered GaAs photoconductive semiconductor switch (PCSS) with low jitter and compact size characteristics. It avoids the high currentsthat are harmful to high-gain mode PCSSs. In the trigger circuit, a 200 pF capacitor is charged by a microsecond-scale 18 kV pulse and thendischarged via the high-gain mode GaAs PCSS to trigger the high-power trigatron switch. When triggered by the ~10 ns pulse generated by thePCSS, the DC-charged trigatron can operate in the 20e35 kV range with 10 ns rise time and 1 ns delay-time jitter.

Delay Trigger in the Application of Network Testing System

The researchers who study the local area network( LAN) eXtension for instrumentation( LXI) instrument are pursuing instrument's high-precision synchronization. In the paper,three synchronization modes were discussed which were clock synchronization, trigger synchronization, and response synchronization. Synchronous process between LXI instruments was analyzed and each time factor affecting the synchronization accuracy was discussed. On the basis of the analysis,it can be found that delay trigger plays an important role in the network testing system's synchronization. Delay trigger can produce an additional time interval to correct the difference of each LXI instrument's response time. Then,a method to realize the delay trigger was introduced. Delay time can be adjustable according to the actual demand. Finally,synchronization accuracy of network testing system can reach nanoseconds.

Multiple attractors and generalized synchronization in delayed Mackey-Glass systems

Nonlinear dynamics of the time-delayed Mackey-Glass systems is explored. Coexistent multiple chaotic attractors are found. Attractors with double-scroll structures can be well classified in terms of different return times within one period of the delay time by constructing the Poincare section. Synchronizations of the drive-response Mackey-Glass oscillators are investigated. The critical coupling strength for the emergence of generalized synchronization against the delay time exhibits the interesting resonant behaviour. We reveal that stronger resonance effect may be observed when different attractors are applied to the drivers, i.e., more resonance peaks can be found.

Synchronization of Stochastic Memristive Neural Networks with Retarded and Advanced Argument

In this paper, we discuss the driving-response synchronization problem for two memristive neural networks with retarded and advanced arguments under the condition of additional noise. The control law is related to the linear time-delay feedback term, and the discontinuous feedback term. Moreover, the random different equation is used to prove the stability of this theory. At the end, the simulation results verify the correctness of the theoretical results.

基于面向TTE的新型数据综合系统的设计与实现

针对传统总线无法实时网络传输,新型总线时间触发以太网(TTE)兼容IP协议和IEEE802.3协议,但TT业务和BE业务需设备满足TTE协议,实际工程缺少适用性的问题,设计了一种基于FPGA的时间触发以太网数据综合系统。该数据综合系统以FPGA作为核心控制器,千兆网作为主要通信接口,在满足高速率、高宽带、高灵活的前提下,设计出数据综合模块,将多种传统总线与TTE总线良好兼容。试验结果表明:系统在同步精度高达40 ns、通信抖动仅为392 ns的前提下,数据转换收发无误码现象。同时将多种数据混合编帧,具备极高的稳定性与灵活性,为TTE网络数据服务于实际工程提供了可靠的解决方案。

机械振动无线传感器簇状网络路径感知同步触发方法

无线传感器可以实时监测机械振动情况,但如果同步触发问题解决不好,可能会直接影响监测效果,导致机械设备无法正常使用。为了从根源上解决这个问题,需要重新研究感知同步触发方法。文章以机械振动无线传感器数据采集为基础,提出了STBTC_P架构与实现,并探讨了簇状网络路径感知同步触发方式,谨供参考。

基于直线轨迹的激光跟踪仪测量精度测试方法

激光跟踪仪测量技术广泛应用于装配、制造等多个领域。为研究激光跟踪仪测量精度,研制了一套以光栅尺采集值为参考,通过多轴运动控制器实现电机运动控制、光栅尺采集、激光跟踪仪测量三者同步触发的坐标测量精度测试系统。对系统重复定位精度与激光跟踪仪同步触发坐标测量精度分别进行了试验。结果表明,系统重复定位误差在[–4.0μm,4.0μm]之间。3台不同型号激光跟踪仪在切向方向上与目标反射镜的距离为[2.7 m,3.4 m]时,其坐标测量误差随速度变化分布在[–23μm,988μm]之间。激光跟踪仪在径向方向上与目标反射镜的距离为[1.5 m,3.8 m]时,其坐标测量误差随速度变化分布在[5μm,915μm]之间。

适用于光导开关触发的V/N气体开关设计与验证

为了满足多路精确同步触发开关要求,将光导开关(PCSS)与V/N气体开关结合,可充分发挥PCSS低触发阈值、低抖动和光电隔离以及V/N气体开关工作电压高、带载能力强等优势。两种开关结合的核心是V/N气体开关结构参数与PCSS触发回路的参数匹配。分析计算了V/N气体开关的结构电容、触发回路振荡参数、开关电场分布等,研究了V/N气体开关的结构电容与PCSS、串联电感等构成的振荡回路的匹配关系,通过实验获得了V/N气体开关自击穿电压曲线、导通延迟时间以及不同欠压比下的延迟时间抖动等,初步验证了适用于PCSS触发的V/N气体开关设计。

安全稳定控制系统远程非实时闭环测试技术研究

目前,安全稳定控制系统的测试主要依赖于相互独立的厂内测试、实验室测试和现场联调测试,难以彻底消除安全稳定控制系统潜在的隐患。针对现有测试方法的不足,提出一种安全稳定控制系统远程非实时闭环测试技术。通过融合硬件在环仿真、5G通信组网、广域同步触发、多通信协议转换等关键技术,研发了平台管理系统、测试主站和测试终端等关键模块,并制定了远程非实时闭环测试流程。以四川电网水电经特高压直流集中送出安全稳定控制系统为例,验证了所提技术的可行性。

基于ZYNQ的时间触发以太网系统设计

时间触发以太网(TTE)是一种基于标准以太网的实时网络通信技术,采用“时钟同步”和“时间触发”来确保关键数据的通信实时性和确定性,解决了标准以太网基于“事件触发”的通信方式无法保证通信确定性这一问题,通过冗余传输和故障检测、隔离机制来提升网络的可靠性,具有大带宽、强实时性、高可靠性和兼容标准以太网的技术特点,能够满足安全关键系统的强实时通信需求,本系统应用ZYNQ芯片实现了TTE网络协议,完成了数据采集、数据传输、数据判读等功能。测试展现了TTE技术的高可靠性和时效性,并展现出本系统的兼容性和多任务工况的应用拓展性。